Complete geometrical query languages (extended abstract)
Marc Gyssens, Jan Van den Bussche, Dirk Van Gucht · 1997
We introduce query languages for spatial databases that are complete, in the sense that they can express precisely all computable queries that are generic with respect to certain classes of transformation8 of space, corresponding to certain geometric interpretations of spatial data.We thus extend Chandra and Hare& seminal work on computable queries for relational databases to a spatial setting.We use a constraint-based spatial data model which model8 spatial data a8 semi-algebraic relations over the real numbers.We also introduce natural point-based geometric query languages that are complete relative to the basic class of queries expressible in the relational calculus with real polynomial constraints.